The aim of the proposed research is to assess the peripheral and central sequelae of trigeminal (V) nerve damage and to define mechanisms underlying injury-induced V reorganization. Anatomical, physiological, immunocytochemical, neurochemical, and computer-assisted morphometric techniques will be used to provide basic data relevant to chronic and acute oro-facial pain, acquired craniofacial anomalies and methods for reconstruction of congenital oro-facial malformations. Seven projects are proposed. Each examines multiple aspects of injury-induced V plasticity and/or normal development in rodents.